The present application relates to communication devices, communication systems incorporating such communication devices and communication methods with the possibility of an online parameter change.
Transmission of data between a transmitter and a receiver, for example wireline transmission like xDSL transmission or wireless transmission, is usually governed by a number of communication parameters which for example determine an amount of protection against various types of noise provided. In some cases, for example when noise conditions change during communication, a change of these parameters may be desirable. Online parameter change is a way of changing such communication parameters without completely stopping and newly setting up the communication connection used, for example without performing a complete handshake, initialization and training procedure performed when initially using a communication connection.
Sometimes in communication systems retransmission is used. Retransmission essentially means that if data sent from a transmitter to a receiver is not acknowledged by the receiver or not acknowledged within a predetermined time period, the data is sent again.
In such a system, when an online parameter change is to be performed, there may still be data left to be retransmitted with the old parameters.
It is therefore an object of the present invention to provide communication methods and communication devices which facilitate coordinating an online parameter change with other aspects of the communication system involved like retransmission.